An apparatus for extruding food dough to encrust a filling material comprises an external cylinder and an inner cylinder placed concentrically. A filling material such as a bean jam is supplied in an inner cylinder part. A crust material for wrapping the filling material is supplied in an annular space between the external cylinder and the inner cylinder placed concentrically. The filling material is extruded from an inner nozzle. Simultaneously, the crust material is extruded from a narrow annular nozzle region between the inner and outer nozzles so that they form a continuous, multi-layered and bar-shaped food dough.
As food dough supplied in an annular space is extruded from a progressively narrower annular nozzle region, the food dough needs to be pressurized for feeding. When the food dough includes small lumps or materials of different properties or does not have a uniform dispersion as a whole, it may not be stably extruded.
According to the prior art, in order to solve such a technical problem, a stirring stick or a stirring feather is installed to be rotated or swung in an annular space between the external cylinder and the inner cylinder to fluidize the food dough therein. But the prior art cannot sufficiently solve the problem of food dough penetrating the seal members arranged between a rotating or swinging body with a stirring stick or a stirring feather and an upper external cylinder or a lower external cylinder such as an external nozzle.
Also, various stresses work on a rotating body with stirring sticks or stirring feathers. The food dough penetrates the sealing members, bearing members supporting the rotating body, and, further a driven gear engaged with the rotating body. Therefore, the food dough penetrating the bearing members and the driving gear greatly increases a frictional force and generates high frictional heat. Accordingly, the rotation of the driven member incorporated in the rotating member is obstructed.
According to this invention, in order to solve such problems, a stirring stick or a sing feather is installed to be rotated or swung in an annular space section between the external cylinder and the inner cylinder to fluidize the food dough therein. Further, a temporary storage space for food dough penetrating the seal members is arranged between the bearing section and the sealing section. Also further, the structure of this apparatus is improved so as to be easily and simply disassembled and reassembled.
Further, according to this invention, the structure of the seal members is improved to control the penetration of food dough through them. Also, in order to facilitate the removal of food dough penetrating the seal members, the structure of the apparatus is improved to be able to be disassembled and reassembled in a simple manner from one direction.